Reamer.



J. G. MATTHEWS.

, REAMER.

APPLICATION FILED AUG. 30, 1806.

Patented Jan. 4, 1910.

UNITED STATES PATENT OFFICE.

JOHN G. MATTHEW S, OF THREE RIVERS, .MICHIGAN.

BEAMER.

Specification of Letters Patent.

Patented Jan. 4, 1910.

Application filed August 30, 1906. Serial No. 332,682. X

useful Improvements in Reamers, of whichv the following is a s ecification.

This invention re ates to improvements in expansible reamers.

Theobjects of this invention are: First, to provide an improved ream'er having-fixed blades of high-grade steel, which is capable of expansion so that the sizeof the tool may be maintained, and, at the same time, one which is comparatively easy and economical to manufacture. Second, to provide an imhigh-grade steel having vas many cutting edges as would ordinarily be found in a solid or non-expansible reamer. .Third, to provide an improved ex ansible reamer hav ing blades of high-gra e steel in which the blades are fixed and supported throughout.

. so that the tool is capable of use in aiiy class of work and ca able of withstanding all the strain to whic a solid or non-expansible reamer may be subjected.

Further objects, and objects relatin to structural details, will definitely appear rom the detailed description to follow.

I accomplish the objects of my invention by the devices and means described in the following specification.

- The invention is clearly defined and pointed out in the claims.

A structure embodying the features of my :invention is clearly illustrated in the accompanying drawing, forming a part of this specification, in which,

Figure 1 is a longitudinal section of a reamer embodying the features of my invention taken on a line corresponding to line 1-1 of Fig. 2. 2 is an'end elevation of the structure a pearing in Fig. 1,-

looldn from the left t ereof. Fig. 3 is a longitudinal section of my im roved reamer in a slightly modified form, ta en on a line corresponding to line 3 3 of- Fig. 4, the expanding plug being solid instead of tubular, as appears in Fig. 1. Fig.4 is an end elevation of the structure appearing 'in' Fig. 3, looking from the left thereof.

5 is a detail lon itudinal section of a further modification, ta en on a line c'orrespondin to line 55 of Fig. 6, in which the longitudinal' slots do not open' at the end of'the tool, the tool being provided with a guide portion A", this form being especially designed for hand tools. Fig. 6i is an end elevation of the structurelapparing in Fig. 5, lookin modification, being particularly a modificafrom the left thereof. Fig. 7 is a. detail ongitudinal section of a further tion of the structure shown in Fi 5, with the threading on the expandin pliig at the outer instead of the inner end t ereof. Fig. 8 is a cross section, taken on-a line corresponding to line 8-8 of Figs. 5 and 7, show.- ing thedetails of the construction and the inserted blades. y Y

In the drawing, the sectional views are A I taken looking in the direction of the little proved expansible reamer having blades of arrows at the ends of the sect-ion lines, and similar letters of reference refer to similar parts throughout the several views.

Referring. to the drawing, the body of the reamer A is formed of soft steel, such steel or material being preferabl which can be quite easil workedan can be. quite readily. expand In the construction shown in Figsl to 4 inclusive, the body is provided with longitudinal slits a opening at-its cutting end. 'In the tool shown in Fig. 1,.the body ismade tubular being particularly designed for large'reaniers.

The blades A are preferably of highusedgrade steel, preferably such as self-hardenmg or air-hardening or high-speed steel,

which are brazed or soldered in their seats, a suitable hard solder being used, the process of uniting the blades to the bod being preferably that described in my app ication greater range of adjustment than would be possible in a tool constructed entirely of high-grade steel. Another very great advantage is that the cutting blades are so supported that they are not likely to be injured in use and are capable of withstand-- mg much greater strain than the blades of the ordinary expansible reamer'having adjustable blades or blades held by mechanical means. The expanding plug B, in the con struction shown in Fig. 1, is threaded into the same, the threaded portion B" being preferably beyond the kerfs or slots therein and the expanding conical portion B of the plug is at its outer end. This enables the more perfect machining of the arts and the expanding portion B may be ardened if desired.

open at the end of the reamers, the reamers being provided with solid portions A" at their ends. These solid portions form guides for the reamer which are of particular advantage in hand reamers, as is well understood in the art. In this construction, the conical or tapered portion of the plug is located at a central point relative to the slots a so that the expansion occurs'at a central point of the blades.

In the construction shown in Fig. 5, the

threads B" are at the inner end of the plug, while in the construction shown in Fig. 7 they are at the outer end.

By supporting the blades of high-grade steel on a soft body, as before stated, I secure all the advantages of the high-grade steel cutting blades. Further, the body of softsteel can be easily machined to receive the expanding plug. The comparatively thin blades are sosupported that they are capable of considerable adjustment and at the same time are not liable to be injured thereby, the expansion being much greater than is possible in a tool made of afisingle piece of hardened steel. A further advantage is that the body can be machined after the blades are hardened, thereby avoiding a liability of distortion of the body and the cracking thereof in hardenin which are characteristics of tools made of single pieces of highgrade steel which harden clear through. Another advantage is that a tool having a solid body, such as is illustrated in my application referred to, may, after the may be machined same has been worn below size by use, be converted into an expansible tool, it being possible to machine the body, as before stated.

In the use of the expression soft steel, I wish to be understood as contemplating'any suitable steel which is relatively soft and or worlied. Some so called tool steel and carbon steels for instance, although they should be hardened at the time of, hardening the blades, might In the modified construction of Figs. 5- to 8 inclusive, the longitudinal slits do not be softened by reheating without destroying the temper of the blades so that they can be quite easily machined.

I have illustrated anddescribed my invention in detail in the form preferred by 65 me, although I am aware that it is capable of considerable variation in structural details without departing from my invention.

Having thus described my invention, what- I claim as new and desire to secure by Lettei's Patent is: 1

1. An exp'ansible reamer, comprising a body of soft metal having longitudinal slits therein; cutting blades of high-grade steel arranged in suitable seats in said divided portion of said bodyand brazed therein; and a tapered expanding plug threaded into saii body to expand said reamer, as speci- 2. An 'ex ansible reamer comprisin a hollow bo y having longitudinals ots therein dividing one end thereof into parts, a portion of the unslitted body being provided with internal screw threads; a tapered expanding plug having a threaded portion 

